code: def hybrid_forward(self, F, x, *args, **kwargs):
      raise NotImplementedError
  
file_path: gluonts/src/gluonts/mx/model/canonical/_network.py
imports: from mxnet.gluon import HybridBlock
  from gluonts.core.component import validated
  from gluonts.mx import Tensor
  from gluonts.mx.block.feature import FeatureEmbedder
  from gluonts.mx.block.scaler import MeanScaler
  from gluonts.mx.distribution import DistributionOutput
label_desc: Use image node_id 3 for calling the CanonicalNetworkBase obj's underlying member method code with example usage: obj.hybrid_forward(F, x) without return types